Meanwhile another ex-Tory joins UKIP
Councillor Suzanne Grocott, the new Conservative group Deputy Leader, represents Dundonald ward and is shadow Cabinet member for finance.
She has lived in Merton for many years and is the mother of a 19-year old-son who is currently studying Engineering at university.
Having worked in the financial services industry for most of her working life, Councillor Grocott says she is looking to use her private sector experience to deliver increased efficiencies to the Council.
On her election at a meeting of the Merton Conservative Group, Councillor Grocott said: "I am delighted that my colleagues have put their faith in me and elected me as their new Deputy Leader.
"I am very excited to be taking on this role in such an important year as we head towards the next set of local elections in May 2014. I look forward to working with our Group Leader, Councillor Oonagh Moulton, and all of my colleagues in the Conservative Group as we set out our positive vision for Merton and ask residents to put their trust in us next year."
Councillor Oonagh Moulton, Leader of Merton Conservatives, said: "I am pleased that Councillor Grocott will be joining me on the frontbench as we take the fight to Labour. I am very fortunate to be able to lead such a talented Shadow Cabinet team and I can assure all of Merton's residents that the sole focus for the Conservative group will be on ensuring that their needs are put first and that Conservative principles are applied to secure delivery of the best value services for them."
The announcement came as a third former local Conservative councillor - Rod Scott - said he was joining UKIP.
The Raynes Park councillor joins Councillor Suzanne Evans and Councillor Richard Hilton, who defected to UKIP last month.
June 14, 2013